BMW B58 Catted Downpipe

The Active Autowerke BMW B58 Catted Downpipe is engineered to unleash the performance potential restricted by the OEM downpipe in B58 engines. By utilizing 4.5-inch diameter 304 stainless steel piping with a 1.5mm wall thickness, it significantly reduces exhaust back pressure, leading to quicker turbo spool, increased horsepower, and improved torque. The piping tapers to 3.5 inches with a stainless flex joint and then to 80mm to mate with the stock exhaust system. This downpipe features a 4.5-inch high-flow GESI G-Sport Ultra High Output Catalytic Converter, which is EPA registered and OBD2 compliant, designed to prevent Check Engine Lights (CELs) in 49 states. The GESI converter is rated for 500-850 horsepower applications and is constructed with a 304 stainless steel substrate. However, it is not legal for use on vehicles registered in California. The downpipe includes a turbo flange gasket, which is pre-installed to prevent damage during installation. A key benefit is that NO PERFORMANCE TUNE IS NEEDED for this downpipe. Fitment is specified for US model cars only; compatibility with non-US models is not guaranteed. Key features include a casted upper stainless steel V-Band for precise fitment, ultra-high flow 400 cells per square inch catalyst, and a durable TIG-welded construction. The downpipe is covered by a 5-year/50,000-mile warranty on the shell and tube ends, and a 2-year/25,000-mile warranty on the catalytic core, though the warranty is voided by excessive burble that can damage the core.